Die-cast motor block



Wan. 7, 1941. c. l... JOHNSON arm. 2,227,500

DIE-CAST MOTOR BLO K 7 Filed Jan. 5, 1938 3 Sheets-She,et 1

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DIE-CAST MOTOR BLQCK Filed Jan. 3, 1938 3 Sheets-Sheet 2 CZarerzceL fa/2726072, 01135 J J0/Z7Z607Z;

Jan. 7, 1941- c. L. JOHNSON ETAL DIE-CAST MOTOR BLOCK 3 Sheets-Sheet 5NNN Filed Jan. 3, 1938 a, wof wwmm mm mm mm WWWM MN z fi m J mJ L 2 Q mmCZ Q k W atented Jan. 7, 1941 UNITED STATES PATENT OFFICE DIE-CAST MOTORBLOCK Application January 3, 1938, Serial No. 182,998

11 Claims.

The present invention relates to die-cast motor blocks.

More particularly the present invention relates to constructions suchfor example as internal combustion motors involving cylinders havingpistons reciprocating therein and a crank case associated with saidcylinders. Economies in manufacture may be effected if the cylinders ofsuch constructions are manufactured by a die casting operation. The diecasting of engine cylinders has not been generally practiced, however,for the reason that the constructions of such motor blocks have notadapted themselves well to the die casting operation.

An object of the present invention is to provide a motor constructionwell adapted to be die cast.

A further object is to provide a cylinder construction having anintegral head portion, which cylinder construction may have the pistonsconveniently mounted therein from the crank case end of said cylinderconstruction.

As a corollary to the last named object, a further object is to providea cylinder construction of the kind referred to in which the bearingsmay be easily mounted and easily held in place, which construction willprovide adequate supporting surface for said bearings.

A further object is to provide a motor block construction which may bedie cast in its manuiacture, which construction is well adapted to meetthe needs of commercial service.

Further objects will appear as the description proceeds.

Referring to the drawings- Figure 1 is a vertical sectional viewillustrating one embodiment of the present invention;

Figure 2 is a view, partly in section, taken along the planes indicatedby the arrows 2-2 of Figure 1;

Figure 3 is a view of the top of a cylinder block of the presentinvention, the cooling jacket covor being. removed;

Figure 4 is a horizontal sectional view taken along the plane indicatedby the arrows 4-4 of Figure 2;

Figure 5 is a sectional view taken along the plane indicated by thearrows Bi -5 of Figure 1 and illustrating a bearing construction whichmay be utilized in practicing the'present invention;

Figure 6 is a sectional View taken along the plane indicated by thearrows 6-45 of Figure 1, and illustrating a construction which may beused for the center bearing of a twin cylinder construction;

Figure '7 is a sectional view somewhat similar to a portion of Figure 1but illustrating a modifled construction in which the split bearings forthe crank shaft may be cast integral with two halves of the crank case;and

Figure 8 is a view illustrating a modified construction which may beused in place of the construction illustrated in Figure 5.

In the drawings, an internal combustion motor of the two-cycle type isillustrated. The numeral Ill indicates a cylinder block comprising twocylinders ll--H. Said cylinders have the heads l2-l2 formed integraltherewith. Surrounding the cylinder block I0 is a water jacket I3, saidwater jacket being enclosed within the wall l4. Said water jacket 13will preferably open toward the head end of the cylinder block l0, andfor purposes of manufacture will be of uniform crosssectionaldimensions, or at any rate will be so formed as to present noobstructions to the withdrawal of the die forming the water cavity.Disposed at the head end of the cylinder block I0 is the water jacketcover l5, which may be secured by bolts or other securing means to thecylinder block Ill. The cover I5 will, 01' course, cover the waterJacket I3, and inasmuch as said water jacket is not subjected to highpressures, no dimculty will be encountered in sealing the cover IE tothe wall It to provide a liquid-tight water cavity. As appears from thedrawings, the bearing of the cover l5 upon the heads i2 is at a planedisposed outwardly of the plane marking its bearing in the jacket walll4.

The cylinder heads I2--l2 will be provided with apertures 16-48, whichmay be screwthreaded for the reception of spark plugs. The water jacketcover I 5 will be provided with apertures |'ll'l for accommodating saidspark plugs.

The two cylinders I l--I l are separated by the partition l8. Thecylinder block I0 is extended below the cylinders l|-H to provide aportion I9 of the crank case, which crank case is indicated as a wholeby the. numeral 20. The crank case 20 is split along a plane whichincludes the axis. of the crank shaft 2|, which plane is disposed atright angles to the axesof the cylinders ll--I l. The lower half of thecrank case 20 is embodied in the closure member 22. Said closure member22 may be held in place by any preferred means, such for example as thebolts 23-23 illustrated in Figures 2, 6 and 8.

Each of the engine cylinders ll may be provided with a bearing sleeveindicated by the numeral 24, which receives the pistons (not shown).Said bearing sleeves 2| -may be made of material highly resistant towear and may be cast in the cylinder block l0 during the die castingoperation.

As indicated hereinabove, the particular embodiment of the presentinvention chosen for illustration is a two-cycle engine. The materialforming the cylinder block adjacent to each cylinder I will be providedwith the U-shaped passageway 25 (Figure 2), whereby communication may beprovided from the interior of the crank case 20 to the explosion side ofeach piston (not shown). This passageway 25 may be formed during the diecasting operation. A plate 26 is provided for defining the outerboundary of said passageway 25. The sleeve 24 will, of course, beprovided with apertures coinciding with the passageway 25, whereby noobstructions will be presented to the flow of gases through saidpassageway 25.

The cylinder block I0 is also provided with intake apertures 21communicating with each cylinder II, which apertures may be connectedwith a carburetor (not shown). The cylinder block I0 is also providedwith exhaust apertures 28f'each comunicating with a correspondingcylinder Each sleeve 24 will, of course, be provided with aperturescommunicating with the corresponding apertures 21 and 28, whereby topresent no obstruction to flow of fluid medium through said apertures 21and 28.

It will be noted that each cylinder i I has its bore extending withundiminished diameter to the crank case 20. By reason of thisconstruction, together with the fact that the lower wall 22 of the crankcase is removable, it is readily possible to assemble pistons within thecylinders and to properly locate the crank shaft 2| with its cranks andpiston rods. The two cranks are indicated by the numerals 29 and 30, andthe crank shaft 2| between said cranks 29 and 30 is provided with abearing split longitudinally. As will be clear from an inspection ofFigure 6, a pair of bearing members 3| and 32 are provided between thecranks 29 and 30, the bearing member 3| being secured to the lowerextremity of the partition I8 by means of the screws 3333, which havetheir heads engaging with opposed edges of the bearing member 3| to holdsaid bearing member in contact with the extremity of the partition l8.The bearing member 32 is similarly held in position in the crank caseclosure member 22.

I In the construction illustrated in Figures 1 to 7, the crank shaft 2|adjacent to its ends outside of the cranks 29 and 30 is provided withcylindrical bearings split longitudinally, the upper bearing member ateach end of the shaft being indicated by the numeral 34 and the lowermember of the bearing being indicated by the numeral 35. Said bearingmembers 34 and 35 at each end of the crank shaft 2| may be secured tothe cylinder block I2 and to the crank case closure member 22,respectively, by any preferred means, such for example as screws 33(Figures 4 and 5) the heads of which engage in recesses in the outerperipheries of said bearing members substantially on chords of saidbearing members. From an inspection of Figure '7 it will be noted thatit is quite feasible to cast the bearing members 3434 integral with thecylinder block IO' and to cast the bearing members 3535 integral withthe crank case closure member 22. Said semi-cylindrical bearings are moued pon c rresponding casings formed integrally with the crank case.

Figure 8 shows a modified construction of bearing for the end portionsof the shaft 21. According to the embodiment illustrated in Figure 8,"the bearings at the two ends of the shaft 2| are cylindrical members,indicated by the numeral 36. Said bearings 36 may be held in place bymeans of the screws 3'|3'|, the heads of which engaged shoulders 38-38milled out on the periphery of the bearing 36.

Assembly of the parts constituting the elements of the illustratedembodiments may be readily accomplished. The center bearing members 3|and 32 will, of course, be located in their operative positionswith'respect to the cylinder block I0 and the crank case closure member22. The bearing members 3434 and the bearing members 3535 will also belocated in their operative positions in the cylinder block l0 and thecrank case closure member 22, respectively.

The crank shaft 2| with its associated pistons and piston rods will thenbe assembled relative to the cylinder block.. l2 with said pistonslocated in the cylinders after which the crank case closure member 22with its bearing members 32 and 3535 will be assembled with respect tothe cylinder block I0 and the crank shaft 2|, said closure member beingtightly secured by means of the bolts 23-23. With the embodiment of theinvention shown in Figure 8, the bearings 36 at each end of the crankshaft 2| will be positioned upon the ends of said crank shaft and willbe secured in position by means of the respective screws 31. The closuremember 22 and crank shaft with its appurtenant pistons and piston rodswill be assembled with respect to the cylinder block Ill.

The invention has the practical advantage that the parts may be die castby simple die casting operations. No difliculties will be encountered ininserting the pistons from the crank case end of the cylinder block.Inasmuch as the greatest efforts upon the bearings are exerted in adirection away from the cylinders no harm can result from the fact thatthe structure involves a smaller area of backing for the crank shaftbearings on the sides thereof adjacent to the cylinders than on theother sides thereof.

The present invention has the further practical advantage that the crankshaft bearings are relatively large in proportion to cylinder diameterwithout involving excessive axial dimensions of the crank shaft, so thatsaid bearings receive substantial support at the sides of the cylinderor cylinders even though the cylinder block is cut away at the crankshaft end thereof to permit the insertion of the piston or pistons atthe crank case end of the cylinder block.

Though certain embodiments of the present invention have been describedin detail, many modifications will occur to those skilled in the art. Itis intended to cover all such modifications that fall within the scopeof the appended claims.

What is claimed is:

1. In an internal combustion motor, a cylinder block having a portion ofa crank case formed integral therewith and also having a cooling waterjacket formed integral therewith, said crank case portion and saidcooling jacket opening in opposite directions and both being free ofprojections which would prevent the withdrawal of a forming dietherefrom, said cylinder head therefor integral with said block, covermeans at the explosion end of said block for closing said water jacket,and a crank case closure member cooperating with saidcrank case portionto form a crank case.

2.111 an internal combustion motor, "a' cylinder block having a portionof a crank case formed integral therewith and also having a coolingwater jacket formed integral therewith, said crank case portion and saidcooling jacket opening in opposite" directions and both being free ofprojections which would prevent the withdrawal of a forming dietherefrom, said cylinder block having a cylinder therein and a cylinderhead therefor integral with said block, cover means at the explosion endof said block for closing said water jacket, a crank case closure member00- operating with said crank case portion to form a crank case, and acrank shaft with its associated bearings embraced between said crankcase portion and said crank case closure member.

3. In an internal combustion motor, in combination, a cylinder blockhaving a portion of a crank .case formed integral therewith, saidcylinder block having a plurality of cylinders, said cylinders havingcylinder heads formed integral with said block, said block having apartition wall between said cylinders formed integral with said block, acrank case closure member cooperv ating with said crank case portion toform a crank case, a crank shaft disposed within said crank case, saidshaft having a plurality of cranks cooperatively associated with saidcylinders, said crank case portion leaving said cylinders unobstructedto permit the insertion of pistons within said cylinders from the crankcase ends thereof,

said shaft being provided with a plurality of bearings including acenter bearing and outer bearings, the end to end distance between saidbearings being less than the diameter of said cylinders, said centerbearing comprising two substantially semi-cylindrical members, onesecured to said crank case portion and the other secured to said crankcase closure member.

4. In an internal combustion motor, a cylinder block having a cylinder,said block having the cylinder head cast integral therewith, a coolingwater jacket for said cylinder opening at the combustion end of saidmotor, and a water jacket cover bearing upon said block and closing saidwater jacket, said cylinder block having formed integral therewith aportion of a crank case, said crank case portion leaving said cylinderunobstructed whereby a forming die may be withdrawn therefrom and apiston may be inserted to fit within said cylinder at the crank case endof said motor, said water jacket being free of obstructions to permitthe withdrawal of a forming die therefrom.

5. In an internal combustion motor, a cylinder block having the cylinderhead and a cooling Water jacket cast integral therewith, said coolingwater jacket opening toward the head end of said block, said waterjacket being free of obstructions to permit the withdrawal of a formingdie therefrom, and cover means docated at the head end of said block forclosing said cooling water jacket, said cover means bearing on saidcylinder head in a plane disposed outwardly of the plane marking itsbearing upon said jacket.

6. In an internal combustion motor, a cylinder block having the cylinderhead and a cooling water jacket cast integral therewith, said coolingwater jacket opening toward, the head end of "water jacket, said covermeans bearing on said cylinder head in a plane disposed outwardly of theplane marking its bearing upon said jacket, said cylinder head having ascrew-threaded opening for a spark plug, said cover means having analigned opening for the reception of said spark plug.

7. In an internal combustion engine, in combination, a cylinder blockhaving a plurality of parallel cylinders, the cylinder heads of saidcylinders and a portion of a crank case being formed integral with saidblock, a crank case closure member cooperating with said portion of saidcrank case, said portion of said crank case and said closure memberhaving cooperating partitions to form crank case compartments for saidcylinders, said compartments in said crank case portion having opposedwalls spaced apart longitudinally of said crank case a distance lessthan the diameter of their corresponding cylinders, a substantiallysemi-circular bearing member carried by said partition forming part ofsaid crank case portion, and a cooperating substantially semi-circularbearing member carried by said crank case closure member, said firstmentioned bearing member being of suificient length to extend beyond theprojected crosssectional areas of said cylinders, said first mentionedbearing member being detachable from said partition whereby it may beremoved from said partition to permit pistons to be entered into saidcylinders from the crank case end thereof, said crank case portion beingshaped to leave said cylinders unobstructed to permit the entry ofpistons to fit said cylinders.

8. In an internal combustion motor, in combination, a cylinder blockhaving a portion of a crank case formed integral therewith, saidcylinder block having a plurality of cylinders, said cylinders havingcylinder heads formed integral with said block, said block having apartition wall between said cylinders formed integral with said block, acrank case closure member cooperating with said crank case portion toform a crank case, and a crank shaft disposed within said crank case,said shaft having a plurality of cranks cooperatively associated withsaid cylinders, said crankcase portion leaving said cylindersunobstructed to permit the insertion of pistons within said cylindersfrom the crank case ends thereof, said shaft being provided with aplurality of bearings including a center bearing and outer bearings, thedistance from said vcenter bearing to said outer bearings being lessthan the diameters of their corresponding cylinders, said center bearingcomprising two halves secured re-.

9. In an internal combustion engine, in combination, a cylinder blockhaving a cylinder therein, said cylinder block having the cylinder headof said cylinder and a portion of a crank case formed integraltherewith, a crank case closure member cooperating with said portion ofsaid crank case to form a crank case con'lpeurt ment, said crank caseportion and said crank case Closure member being joined in a plane whichincludes the axis of said crank case, and journal bearings carried bysaid crank case portion and by said crank case closure member, the wallsof said compartment and said journal bearings being spaced apart lessthan the diameter of said cylinder but shaped to leave said cylinderunobstructed to permit the entry of a piston to fit said cylinder,certain of said journal bearings being split into halves, certain ofsaid halves being integral with said crank case portion and certain ofsaid halves being integral with said closure member, said half securedto said closure member extending well within the projectedcross-sectional areas of said cylinder.

10. In an internal combustion motor, in combination, a cylinder blockhaving a. portion of a crank case formed integral therewith, saidcylinder block having a cylinder, said cylinder having a cylinder headformed integral with said block, a crank case closure member cooperatingwith said crank case portion to form a crank case compartment, a crankshaft disposed axially of said compartment, said shaft having a crankcooperatively associated with said cylinder, said crank case portionleaving said cylinder unobstructed to permit the insertion of a pistonwithin said cylinder from the crank case end thereof, said shaft beingprovided with bearings, the distance between said bearings being lessthan the diameter of said cylinder, each of said bearings comprising twohalves secured respectively to said crank case portion and to said crankcase closure member, said halves secured to said crank case portionhaving its ends shaped to conform to the contour of the wall of saidcylinder whereby to avoid obstructions to the entry-of a piston to fitwithin said cylinder.

11. In an internal combustion engine, in combination, a cylinder blockhaving its cylinder head integral therewith and including a portionformed integral therewith to form a part of a crank case, said cylinderblock including a cylinder adapted to receive a piston, a crank caseclosure member adapted to cooperate with said part of said crank case toform a crank case, journal bearings, certain of said journal bearingsbeing split longitudinally to form halves, certain of said bearinghalves being secured to said crank case portion, the other of saidbearing halves being secured to said closure member and extending wellwithin the projected cross sectional area of said cylinder, said halfwhich is secured to said crank case portion being integral therewith andbeing shaped to conform to the wall of said cylinder whereby to permitentry or withdrawal of said piston from said cylinder.

CLARENCE L. JOHNSON. LOUIS J. JOHNSON.

